Adafruit PN532 NFC/RFID controller breakout board Microcontroller POCSAG pagers

POCSAG pagers

Its an  ESP8266 WiFi module with all the extras you need

They use constant-current drivers for ultra-bright

and a spot to solder in a volume pot

ENABLE pin so you can turn off the module using any microcontroller pin or switch

Adafruit PN532 NFC/RFID controller breakout board Microcontroller POCSAG pagersThe PN532 is the most popular NFC chip, and is what is embedded in pretty much every phone or device that does NFC. It can pretty much do it all, such as read and write to tags and cards, communicate with phones (say for payment processing), and 'act' like a NFC tag. If you want to do any sort of embedded NFC work, this is the chip you'll want to use! NFC (Near Field Communications) is a way for two devices very close to each other to communicate.